Shrinkage test is conducted to check the ______ of the concrete.

• A. Compressive strength
• B. Density
• C. Cracking
• D. Water absorption

Answer: (C)

Shrinkage causes concrete to change in length as it loses moisture during curing. When this shrinkage is restrained by forms, reinforcement, or adjacent concrete, tensile stresses develop and cracks can form. A shrinkage test specifically gauges how much shortening occurs and, more importantly, the tendency for those shrinkage strains to produce cracking. That’s why cracking is what this test assesses. Compressive strength, density, and water absorption relate to other properties (how much load the concrete can carry, its mass per volume, and porosity-related absorption) and are not the focus of a shrinkage test.